西瓜噬酸菌磷酸盐特异性转运系统pstS基因功能分析  

Functional analysis of the pstS gene of the phosphate specific transport system of Acidovorax citrulli

作　　者：蔡馥宇 费诺亚 乔培 关巍[1] 杨玉文[1] 叶云峰[3] 赵廷昌[1] CAI Fuyu;FEI Nuoya;QIAO Pei;GUANWei;YANG Yuwen;YE Yunfeng;ZHAO Tingchang(State Key Laboratory for Biology of Plant Diseases and Insect Pests/Institute of Plant Protection,Chinese Academy of Agricultural Sciences,Beijing 100193,China;Shenyang Agricultural University,Shenyang 110866,Liaoning,China;Horticultural Research Institute,Guangxi Academy of Agricultural Sciences,Nanning 530007,Guangxi,China)

机构地区：[1]植物病虫害生物学国家重点实验室·中国农业科学院植物保护研究所,北京100193 [2]沈阳农业大学,沈阳110866 [3]广西壮族自治区农业科学院园艺研究所,南宁530007

出　　处：《中国瓜菜》2022年第10期16-25,共10页China Cucurbits And Vegetables

基　　金：国家西甜瓜产业技术体系(CARS-25);科技兴蒙行动重点专项(NMKJXM202107-03);中央级公益性科研院所基本科研业务费专项(S2019XM06);中国农业科学院创新工程(CAAS-ASTIP);新疆生产建设兵团科技攻关项目(2202AB015);国家重点研发计划(2018YFD0201300);国家青年基金(31701754)。

摘　　要：以西瓜噬酸菌(Acidovorax citrulli)Aac5菌株为研究对象,构建了pstS基因的缺失突变菌株和互补菌株,进行了致病能力及生物学表型的测定,并通过荧光定量PCR分析了pstS缺失对西瓜噬酸菌致病相关基因和磷酸盐特异性转运系统相关基因表达量的影响。此外,测定了西瓜噬酸菌的PstS蛋白在大肠杆菌中表达时对Pi的结合能力。结果表明,pstS的缺失,降低了西瓜噬酸菌的致病能力、运动能力、体外生长能力和生物膜形成能力,但不影响西瓜噬酸菌诱导烟草产生过敏性坏死反应的能力。pstS缺失后Ⅲ型分泌系统基因hrpG、鞭毛基因fliC、毒力相关基因virB、趋化性相关基因cheA、群体感应基因luxR的相对表达量显著上调,Ⅲ型分泌系统基因hrpX的相对表达量下调。磷酸盐特异性转运系统相关基因Aave_2627、Aave_2628、Aave_2629、Aave_2631和Aave_2632表达量均上调。经PstS对Pi的结合能力试验,证明在大肠杆菌中异源表达的PstS蛋白具有Pi结合能力。研究表明,pstS在西瓜噬酸菌致病能力和Pi转运吸收过程中的Pi结合环节起到重要作用。In this study, Acidovorax citrulli Aac5 strain was used to construct pstS mutant strain and its complementary strain. The pathogenicities and biological phenotypes of different strains were determined, the effect of pstS deletion on the expression of the pathogenicity-related genes and the phosphate specific transport system-related genes of A. citrulli was analyzed by qRT-PCR and the ability of binding Pi when PstS protrin heterologously expressed in E.coli. The results showed that the absence of pstS reduced the pathogenicity, swimming motility,biofilm formation ability and growth ability of A. citrulli, and did not affect the ability of inducing hypersensitive reaction in non-host plants. The relative expression of type Ⅲ secretion system gene hrpG, flagellar gene fliC, virulence-related gene virB, chemotaxis-related gene cheA, and quorum sensing gene luxR were up-regulated, and the expression of type Ⅲ secretion system gene hrpX was down-regulated. The relative expression levels of phosphate specific transport system related genes Aave_2627, Aave_2628, Aave_2629, Aave_2631 and Aave_2632 were all up-regulated. The Pi-binding ability test of PstS proved that the PstS protein heterologously expressed in E. coli has Pi-binding ability. In conclusion, pstS plays an important role in virulence of A.citrulli and the Pi binding link in the process of Pi transport and absorption.

关 键 词：西瓜噬酸菌 磷酸盐特异性转运系统 pstS 

分 类 号：S651[农业科学—果树学]